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Understanding the Kidney and Kidney Disorders, Part 2

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Stage I: Is marked by an increased blood flow through the glomeruli, which increases pressure in the kidneys and makes them appear enlarged. Many people with diabetes never advance beyond stage I.

Stage II: Defined as small amounts of albumin (a blood protein) leaking into the urine. This protein loss is known as microalbuminuria. People with diabetes can stay for many years in stage II.

Stage III: Characterized by increased damage to the glomeruli. Some patients now also develop hypertension. Detecting albumin is done with a urine dipstick test. Blood tests will reveal higher creatinine and urea nitrogen levels, waste products that healthy kidneys would eliminate.

Stage IV: Blood levels in stage IV show even higher creatinine and urea nitrogen levels. Urine protein markedly increases as the glomeruli lose their blood-filtering capabilities. Hypertension is almost certain.

Stage V: In stage V, kidney function has fallen to less than 25% of normal. Stage V is considered End Stage Renal Disease (ESRD) when kidney function is 10% of normal and dialysis or kidney transplant is required. Diabetes and hypertension are the top two causes of ESRD.

Hypertension (high blood pressure) can be both a cause and effect of kidney damage. High blood pressure makes your heart work harder and, over time, can damage blood vessels throughout your body. If the blood vessels in your kidneys are damaged, they may stop removing wastes and extra fluid from your body. The extra fluid in your blood vessels may then raise blood pressure even more. The result is a very unhealthy cycle. Although most people with high blood pressure do not have a kidney problem, the combination of frequent urination and high blood pressure will suggest the possibility, especially if there is a history of kidney trouble in your family.

The key to kidney disease is early detection. If kidney disease is detected in the earliest stages, kidney dysfunction can be stopped or reversed with treatment. The best way to assure early detection of kidney dysfunction is by doing a urine test that measures the levels of a protein called microalbumin.

* Harvard Medical School's Consumer Health Information